- Email: [email protected]
Non-contact measurement
Another part of the project, in this case in conjunction with the Queen Mother's Hospital (Glasgow); is a similar system to display ultrasonographs of the uterus. High frequency acoustic waves are used in medicine for indirect visualization of soft tissues and where x-radiation is harmful. Each ultrasonograph refers to a particular cross-section of the womb. By successively exposing each ultrasonograph in its correct relative position on a single photographic plate, simultaneous viewing of all images is possible on reconstruction. An obvious problem with these techniques is the lengthy preparaton involved.
* Hall, A. M.
Holographic display of data from ultrasonic scanning. Ultrasonics, Vol. 7. pp. 27 -9.
NON-CONTACT MEASUREMENT
The Teramet non- contact position measurement deVice, for industrial use using microwaves and based on optical principles has been developed by the NPL. A cheap and compact instrument based on the Michelson interferometer, it uses a standard quartz iodine projector lamp as a broad-band millimeter wave source to produce 'white light' fringes. The phase of millimeter wave radiation is preserved upon reflection from a machined metal surface as the surface variations are smaller than the wavelengths (501000jlm) This enables the optical components to be produced cheaply by machining, the mirrors being made of metal and the lens and beam splitter from plastic.
The compact arrangement of the instrument is shown in the diagram. The oscillating mirror in the reference arm of the interferometer provides a direction sensitivity by introducing phase modulation, giVing no signal at zero relative displacement and a sharp maximum and minimum on either side of this position. The detector is a Golay cell feeding an amplifier to produce a control signal. This signal can be used to position the reference mirror for zero output the mirror being fitted with a distance scale. An accuracy of 2. 5jlm is claimed. It is envisaged that the instrument will be particularly
useful for determining the position of hot, mOVing or inaccessible surfaces.
Non Ionizing Radiation A NEW international journal NON IONIZING RADIATION will be published on roth June. It covers the effects, hazards and application of electromagnetic radiation from radio frequencies through microwaves and infra-red to the visible region. It is the only journal to combine these subjects exclusively under one cover and to present a comprehensive source of information to workers in the field and to those who need to know about the uses, effects and safety of electromagnetic radiation.
Guided by an international panel of advisory editors, the journal arranges review articles as well as publishing original R&D papers. Introductory and interpretive articles for those without specialised knowledge are featured.
Abstracts of significant papers published in the literature keep the reader abreast of developments. Case studies of installations using radiation for industrial applications, for example microwave drying, are presented, and experimental techniques including power and energy measurement and monitoring are included. The first issues contain papers read at the University of Surrey symposium on Radio and Microwave Radiations-Applications and Potential Hazards. Subscriptions can be obtained from NON IONIZING RADIATION~ Iliire Science and Technical Publications Ltd~ 32 High Street~ Guildford~ Surrey. Annual subscription £10 ($25). Advertisement enquiries should be addressed to T. S. Goldsmith and intending contributors should contact the editor at the above address.
Optics Technology May 1969
173
* Hall, A. M.
Holographic display of data from ultrasonic scanning. Ultrasonics, Vol. 7. pp. 27 -9.
NON-CONTACT MEASUREMENT
The Teramet non- contact position measurement deVice, for industrial use using microwaves and based on optical principles has been developed by the NPL. A cheap and compact instrument based on the Michelson interferometer, it uses a standard quartz iodine projector lamp as a broad-band millimeter wave source to produce 'white light' fringes. The phase of millimeter wave radiation is preserved upon reflection from a machined metal surface as the surface variations are smaller than the wavelengths (501000jlm) This enables the optical components to be produced cheaply by machining, the mirrors being made of metal and the lens and beam splitter from plastic.
The compact arrangement of the instrument is shown in the diagram. The oscillating mirror in the reference arm of the interferometer provides a direction sensitivity by introducing phase modulation, giVing no signal at zero relative displacement and a sharp maximum and minimum on either side of this position. The detector is a Golay cell feeding an amplifier to produce a control signal. This signal can be used to position the reference mirror for zero output the mirror being fitted with a distance scale. An accuracy of 2. 5jlm is claimed. It is envisaged that the instrument will be particularly
useful for determining the position of hot, mOVing or inaccessible surfaces.
Non Ionizing Radiation A NEW international journal NON IONIZING RADIATION will be published on roth June. It covers the effects, hazards and application of electromagnetic radiation from radio frequencies through microwaves and infra-red to the visible region. It is the only journal to combine these subjects exclusively under one cover and to present a comprehensive source of information to workers in the field and to those who need to know about the uses, effects and safety of electromagnetic radiation.
Guided by an international panel of advisory editors, the journal arranges review articles as well as publishing original R&D papers. Introductory and interpretive articles for those without specialised knowledge are featured.
Abstracts of significant papers published in the literature keep the reader abreast of developments. Case studies of installations using radiation for industrial applications, for example microwave drying, are presented, and experimental techniques including power and energy measurement and monitoring are included. The first issues contain papers read at the University of Surrey symposium on Radio and Microwave Radiations-Applications and Potential Hazards. Subscriptions can be obtained from NON IONIZING RADIATION~ Iliire Science and Technical Publications Ltd~ 32 High Street~ Guildford~ Surrey. Annual subscription £10 ($25). Advertisement enquiries should be addressed to T. S. Goldsmith and intending contributors should contact the editor at the above address.
Optics Technology May 1969
173